Before his resignation, Mr Hughes had been due to appear before the Treasury select committee on Tuesday morning to answer questions on early release of the document, which contained details of all the major announcements to come, including £26bn of tax rises and scrapping the two-child cap on child benefit.
However, he has now pulled out of his appearance, meaning that MPs will not get the chance to question Mr Hughes on whether he thought Ms Reeves misled the public about the scale of financial pressures before her Budget.
Instead, the other two members of the three-man OBR’s Budget Responsibility Committee will appear: Prof David Miles and Tom Josephs.
The OBR report revealed that the Economic and Fiscal Outlook was available online between 11.30am and 12.08pm, and was accessed 43 times by 32 unique users during that time.
The web address was the same as the one used for the fiscal statement in March, with only the month changed, making it relatively easy for people to find the documents.
The first access was made at 11.35am by a user who had tried to connect to it on more than 30 previous occasions.
At 11.41am, the details were leaked by Reuters – almost an hour before the Chancellor’s fiscal statement, which began just after 12.30pm.
On Monday morning, Sir Keir Starmer accused the watchdog of having made a “serious error” by publishing the document early.
“I’m not going to suggest that what happened last week, which was the entire Budget being published before the Chancellor got to her feet, was not anything other than a serious error,” the Prime Minister said. “This was market-sensitive information.”
